CVE-2001-1043 in FTP Server
Summary
by MITRE
ArGoSoft FTP Server 1.2.2.2 allows remote attackers to read arbitrary files and directories by uploading a .lnk (link) file that points to the target file.
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Analysis
by VulDB Data Team • 05/22/2019
The ArGoSoft FTP Server version 1.2.2.2 contains a critical directory traversal vulnerability that enables remote attackers to access arbitrary files and directories on the affected system. This vulnerability stems from the server's improper handling of .lnk files during the upload process, creating a path traversal condition that bypasses normal file access controls. The flaw exists in the server's file system interaction logic where it fails to properly validate or sanitize file paths when processing symbolic link references, allowing malicious users to craft specially formatted .lnk files that can reference files outside the intended upload directory.
This vulnerability operates through a classic path traversal attack vector where the malicious .lnk file contains a reference to a target file using relative path components such as ../ or ..\ sequences. When the FTP server processes this file, it follows the symbolic link reference without proper validation, effectively allowing attackers to navigate the file system hierarchy and access sensitive files that should remain protected. The impact is particularly severe because the vulnerability does not require authentication for exploitation, making it accessible to any remote attacker who can establish an FTP connection to the vulnerable server.
The operational impact of this vulnerability extends beyond simple information disclosure, as attackers can potentially access system configuration files, user credentials, application data, and other sensitive resources that may contain critical system information. The vulnerability affects the fundamental security model of the FTP server by allowing unauthorized access to files that should be restricted to specific users or groups. This represents a failure in the server's input validation and access control mechanisms, creating a persistent security weakness that can be exploited repeatedly without detection.
Security professionals should consider this vulnerability in the context of CWE-22, which describes improper limitation of a pathname to a restricted directory, and its relationship to the ATT&CK framework's privilege escalation and credential access techniques. The vulnerability demonstrates how seemingly benign file processing operations can introduce critical security flaws when proper input sanitization is not implemented. Organizations should immediately implement mitigations including updating to a patched version of the ArGoSoft FTP Server, implementing network segmentation to limit FTP access, and deploying intrusion detection systems to monitor for suspicious .lnk file uploads. Additionally, administrators should conduct thorough audits of all FTP server configurations and ensure that proper file access controls are in place to prevent similar path traversal vulnerabilities from existing in other services.